Hall effect devices are used in various applications. One application that Hall effect devices are used is in the area of current sensors. A typical integrated planar Hall effect device is shown in FIG. 1A. As shown in FIG. 1A, the Hall effect device has two pairs of connectors (a first pair of connectors C1 & C2, and a second pair of connectors C3 & C4). FIG. 1B schematically shows the Hall effect device in FIG. 1A with a cross-section view along the CP slice. As shown in FIG. 1B, the connectors are N-type highly doped regions (N+) formed in an N-type well region (N-well), which is formed on a P-type substrate (P-sub). When a magnetic field B is applied perpendicular to a plane of the Hall effect device, and a current is applied to one pair of the connectors (e.g. C1 & C2), a Hall voltage will be generated in the other pair of the connectors (e.g. C3 & C4). A depletion layer which functions as an isolation layer is generated at the junction of the N-well and the P-sub when the current is applied to the Hall effect device and an appropriate voltage level is applied to the P-sub with respect to the voltage level of the connectors.
However, the accuracy of current sensing based on Hall effect devices may suffer from parasitic field and temperature drifts of the magnetic field B, and parasitic spikes due to switching of power switches in a power stage. Efforts such as spinning current technique which controls the current applied to the Hall effect device and the resulted Hall voltage to be spinning between the two pairs of the connectors are adopted to alleviate the current sense accuracy issues, but further improvement is still needed.